1. Field of the Invention
This invention relates to a method for printing out characters represented by input codes; more particularly it relates to a method for deriving from input codes information for positioning a print wheel to present a character for printing and information for controlling the force of print impact.
2. Description of Related Art
Machines of the above-mentioned kind often contain a so-called single element type carrier, such as a spherical head or a typewheel disposed opposite a platen. Located between the single element type carrier and platen are usually a ribbon and a record carrier. These machines produce type impressions of uniform print density by impacting the character to be reproduced and positioned at a printing position with a selected force or intensity level depending on the size of the character.
In machines as described above a control system is necessary to obtain from a code generated by actuating a key or provided by an external apparatus, such as a data processing system, information on the location on the single element type carrier of the type character to be printed, as well as information on the force with which the character to be printed must be accelerated towards the record carrier. Heretofore this has been accomplished in that the said code was converted into character positioning information and impact intensity information, using at least two tables stored in a memory. An example of such a control concept can be found in DE-PS No. 25 29 310 corresponding to U.S. Pat. No. 4,118,129.
In U.S. Pat. No. 4,118,129, the positioning and harmer intensity information were stored in tables comprising upper and lower halves of a ROM and the information was obtained by sequentially addressing first the upper half, and then after the type wheel was positioned, the lower half.
While this procedure is very simple, it has a serious disadvantage. Considering that in today's typewriters or printers different type carriers with different type faces of uniform and/or proportional pitch are used, it becomes clear that different tables are required to determine the hammer intensity information, as a function of the respective kinds of type face. The number of tables required increases further if one considers that, depending on the number of copies to be made, manifold settings establishing different basic typing forces for one and the same set of characters must be realised.